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One ram slot not working in 2009 Macbook Pro

It took me a while to figure this out, but it looks like I have one malfunctioning RAM slot in my macbook Pro (the deeper of the two slots). I have a MBP 5,4


I was running 4x2 for approx 2 years with no issue, then suddenly the comp began freezing shortly after start up.. probably when I started accessing the second RAM slot.


I purchased 2 new 4gb sticks, assuming one or both of the other two were bad. Here is the anaylisis thus far:

1 4gb stick in outer slot - Everything works fine

2 4gb sticks - new RAM or old ram - system freeze


After runing on 8gb for so long, 4 seems terribly slow. Does anyone have any suggestions on how to fix this, or better diagnose the problem?


Thanks,

Nate

MacBook Pro, OS X Mountain Lion (10.8.2)

Posted on Feb 20, 2013 8:16 AM

Reply
5 replies

Feb 20, 2013 8:27 AM in response to DocRocket

You probably also tried working memory in the deeper of the two slots by itself, and if so, the system just beeped at you? That would confirm your diagnosis. I'd probably also run the extended mode of the Apple hardware test to see what it picks up (test can take over an hour to run).


Assuming that one slot is dead, do you have AppleCare (may have run out already)? If not, fixing it generally means replacing the logic board. So, you can stick with 4GB in the working slot or replace the logic board. The system will seem a little slower, because the Intel architecture runs a little bit quicker (3% to 5%) with two matched memory cards.

Dec 9, 2013 12:48 PM in response to DocRocket

I had the same problem a couple of days ago.

So I cleaned the dead slot with an eraser, and than removed the erase dust with a regular brush and after I used a mechanic pencil to put grafit on the slot so it would be more conductive.

My Macbook finaly turned on with the 2 slots working.

I still need to wait for a few days to be sure that the problem will not come back, but than I just have to try the same procedure.

Oct 3, 2014 12:21 PM in response to DocRocket

You should look at this thread MacBook Pro loses access to 1 memory slot upon shutdown or reboot in OS X 10.8.1

I'm having the same issue with a Mid-2011 Mac Mini (purchased 2013). As in that linked tread, overheating after OS upgrade (in my case , Mavericks) seems to be related. I had constant crashes at sleep beginning about three weeks ago, and three tones at boot. For about two weeks I could get it to reboot by unplugging and giving it some time. Until today. Cleaned. Tested both chips in both possible slots, but will always get three tones when either chip is in top slot, fine when that slot is empty. Hardware test appears to just ignore an empty slot, so really not helpful (and won't boot with filled slot).


I'm not going to get into "loosening screws" as suggested in linked discussion, but that may work for a powerbook. It sounds like heat related warping. I saw early problems with this after 10.9.5 upgrade. Ended up building a special vertical stand (Mini's venting is rather poor) and installed "Temperature Monitor" by Marcel Bresink Software, which I recommend. This got the heat under control, but it looks like the damage was done. Now I'm running on 8gb memory, which dramatically shortens the life of the machine. It won't be a candidate for a Yosemite upgrade coming shortly.


Must say I'm pretty disappointed in "Apple quality". Had similar experience (repeated shorts of logic board, replaced 3 times) with a MacBook c.1997, when Apple Co. was looking like it might not survive, and lots of folks were having such problems. But at least then they would repair it for free. Given the premium price (without premium quality), I think this will be my last Mac, after having started with a Plus in the 1980s.

One ram slot not working in 2009 Macbook Pro

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